That type of question comes up a lot - and it really does vary person to person, but the safe to bet on answer is no. There are far more creative ways to scare that can be mixed with screaming - to keep your throat nice and happy. Make a back story and dive into your character to come up with creepy lines that really stick to people a lot more so than just that startle scream. You never here a customer leaving a haunt saying "did you hear how loud that girl screamed at me?" - but you will here "remember in the nursery room when the doll character told me she wanted to use my intestines as a jump rope!?!?"